def import_cities_to_redis(conn,filename):
    for row in csv.reader(open(filename,'rb')):
        if len(row)<4 or not row[0].isdigit():
            continue
        row=[i.decode('latin-1') for i in row]
        city_id=row[0]
        country=row[1]
        region=row[2]
        city=row[3]
        conn.hset('cityid2city:',city_id,json.dumps([city,region,country]))